From vitamin D to skin cancer: what UV radiation really does to your skin

Summer sunshine lures people outdoors, but excessive UV radiation can damage skin in a short period of time. It is important to understand the main effects of this radiation on the body and how to protect yourself from health risks.

Summer sun draws people to spend time outdoors, but ultraviolet radiation – or UV radiation – is a double-edged sword: it is both necessary for the body and potentially dangerous. Moderate sunlight is essential for the body, yet prolonged or unprotected exposure to UV rays can cause serious damage to the skin.

Benefits and harms go hand in hand

The most positive aspects of UV radiation are linked to vitamin D production. The skin synthesises vitamin D precisely through the action of sunlight, which in turn supports bone health, immune system function, and mood. A brief exposure – around 15 to 20 minutes – of sunlight on legs and arms can be entirely sufficient for the body to get its daily dose.

However, the harmful effects of UV radiation are well documented. Rays are divided mainly into two types: UVA rays penetrate deeper into skin layers and accelerate skin ageing, causing wrinkles and age spots. UVB rays, in turn, affect the outer layers of the skin and are the primary cause of sunburn.

Skin damage and cancer risk

Repeated sunburns, especially in childhood and youth, significantly increase the risk of skin cancer later in life. Melanoma, the most dangerous form of skin cancer, is strongly associated with intense and intermittent exposure to UV radiation. Other forms of skin cancer, such as basal cell carcinoma and squamous cell carcinoma, are usually linked to long-term cumulative UV exposure.

How to protect yourself?

Prevention starts with using protective cream – it is recommended to wear sunscreen with at least SPF 30 and reapply it every two hours, especially after swimming or sweating. Additionally, UV-blocking sunglasses, densely woven clothing, and seeking shelter from sun umbrellas during the strongest solar radiation help protect your skin. In Estonia, the strongest sun radiation occurs roughly between 11:00 and 15:00. It is important to remember that even on cloudy days, some UV radiation reaches the ground and your skin.